Power over Ethernet (Power Over Ethernet in English, POE for short) is a technology of supplying direct current to IP-based terminals (such as an IP telephone, a wireless local area network access point AP, and a network camera) while transmitting data signals for such terminals without modifying an existing basic cabling structure of the Ethernet. A PoE system includes a power sourcing equipment (Power sourcing equipment in English: PSE for short) and a powered device (Powered device in English, PD for short).
Currently, the PoE technology is applied to people's life more and more widely, an increasingly high proportion of PoE ports are applied in electrical interface switches of the Ethernet, and more and more types of devices are supported by the PoE.
In the working state, the PSE detects whether a PD is connected to a port of the PSE. If it is detected that a PD is connected to a port, the PSE identifies the type of the PD, evaluates the power loss required by the PD, and starts supplying power to the PD. If no PD is connected to the ports of the PSE, all ports of the PSE keep detecting. The continuous detection leads to continuous consumption and waste of power.